Measures to reduce damage to the ozone layer are having some success, according to the latest four-yearly report on the state of the planet's ozone layer.

The report, released last month by the World Meteorological Organisation and the United Nations Environment Programme, predicts that global ozone will build up so quickly that the Antarctic ozone hole might start to shrink within the next decade.

The Montreal Protocol — an international treaty to eliminate the production and consumption of ozone-depleting chemicals such as chlorofluorocarbons — is working, according to the report. "The ozone-layer depletion from the Protocol's controlled substances is expected to begin to ameliorate within the next decade or so," it states.

But the report warns that this improvement will only occur if climate change does not have any unexpected effects on the ozone layer, and if signatories to the Protocol continue to meet their obligations. "Failure to comply with the Montreal Protocol would delay or could even prevent recovery of the ozone layer," it says.

More than 180 countries have so far ratified the treaty. Further reductions in the production of ozone-destroying chemicals will be required in the next few years, especially by developing countries, which were given a 10-year 'period of grace' under the agreement.